This study calculated the stresses and deformations of the acrylic tanks used in neutrino experiment under dynamic loads and evaluated the safety level of those tanks. The diameters of those large t tanks are ??3m and the thickness of their walls are only 10mm. The measured mechanical properties are: EB=2.95GPa ??8%, SY=77.92 ??7%, SU= 102.13MPa ??12%. The stress distributions of the tanks were simulated by finite element analysis (FEA) software COMSOL and ABAQUS. The dynamic load conditions are vertical upward and horizontal acceleration pulses. The result shows that empty 3m acrylic tank can at least safely sustain 0.3g acceleration. For a 3m tank filled with liquid, the pressure wave of solid-liquid coupled vibration may destroy the tank without reinforced ribs on top lid.